1. Field of the Invention
The present invention relates to a container for fluid materials. More specifically the present invention is a generally tubular container with flexible walls which may be collapsed sequentially utilizing improved interlocking internal members to dispense the material held therein.
2. Description of Related Art
Dispensing tubes for fluid or semi-solid materials such as toothpaste are well known. The majority of these tubes provide a flexible housing or envelope defining an internal cavity to be filled with the material to be dispensed. These tubes generally have a single open end which is selectively sealable with a cap or other structure. The material in these tubes is dispensed by removing the cab and pressing or squeezing the tube.
While this is generally effective, inefficiencies arise whesn a tube of this type is squeezed at any point other than the base of the tube causing some portion of the material to be displaced rearward toward the base of the tube as well as forward toward the open end of the tube. This becomes a significant problem as the tube becomes less full.
One way of dealing with this problem is to roll the tube up from its base to form a transverse closure band across the breadth of the tube. The transverse closure band limits the rearward displacement of the material held in the tube thereby allowing a portion of the remaining contents to be dispensed effectively. This can be an awkward and inefficient procedure as the tube often becomes unrolled either due to the resilience of the tube wall or due to improperly squeezing the tube an some point other than the base of the tube.
Many dispensing tubes attempting to make it easier to dispense the material contained therein have been disclosed in the relevant art. These have included dispensing tubes adapted to partially prevent rearward displacement of the material contained therein during dispensing, dispensing tubes with flexible walls which collapse in different configurations to force the material held therein out of an opening in the tube, and dispensing tubes which rely on an attachable device to aide in dispensing of the material held therein.
U.S. Pat. No. 5,169,030, issued Dec. 8, 1992 to Jack R. Lewin, discloses a flexible walled dispensing tube which partially prevents the rearward displacement of the material contained therein during dispensing through the use of flexible diaphragm members which divide the tube into several chambers. Each diaphragm member has a one way valve therein which allows the material in the tube to pass through each diaphragm toward the tube opening while preventing the material in one chamber from passing into a rearward chamber.
U.S. Pat. No. 2,891,700, issued Jun. 23, 1959 to Michael Maynard, discloses a dispensing tube having, in one embodiment, projections formed on the inner surface of the flexible walls of the tube. The projections prevent a transverse closure band from being formed inside the tube to avoid trapping a portion of the material contained in the tube rearward of the transverse closure band so that the contents of the tube may be completely dispensed.
U.S. Pat. No. 4,235,653, issued Nov. 25, 1980 to Steben Ausnit, discloses a container formed of a flexible web folded into an open mouth bag. The flexible walls of the bag have releasable interlocking fasteners formed on their inner surfaces which act to hermetically seal the bag.
U.S. Pat. No. 3,946,903, issued Mar. 30, 1976 to Carol Parker, discloses a dispensing tube having flexible walls that are spirally fluted. The walls of the dispensing tube of Parker are adapted to collapse in accordion fashion as the bottom of the tube is twisted to force the material out of the opening in the top of the tube.
U.S. Pat. Nos. 2,268,993, issued Jan. 6, 1939 to Rudolph M. Sanders, 2,250,022, issued Jul. 22, 1941 to Malcom E. Hofman, and 2,649,995, issued Aug. 25, 1953 to Nathan Muskin, disclose dispensing tubes having flexible walls which collapse in accordion fashion when the rearward end of the tube is urged toward the opening in the tube to dispense the material contained therein.
U.S. Pat. No. 5,361,939, issued Nov. 8, 1994 to James A. Robertson, Jr., discloses a dispensing tube which utilizes an attachable retaining device that holds the tube in a rolled position as it is being collapsed. The retaining device must be detached in order to continue to roll the tube and then reattached after each use to hold the tube in the rolled position.
U.S. Pat. Nos. 1,286,875, issued Dec. 3, 1918 to William E. Emmerson and 3,155,281, issued Nov. 3, 1964 to John Stracey, disclose dispensing tubes having flexible walls that are collapsed in accordion fashion as the material held therein is being displaced. The dispensing tubes of Emmerson and Stracey utilize threaded base members which act to collapse the dispensing tubes when the base members are twisted.
However, none of the related art discloses a flexible walled dispensing tube having interlocking fasteners formed on the inner surface of the flexible walls which form transverse closure bands in the tube to help prevent the rearward displacement of the material held therein as the material is being dispensed.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus a collapsible dispensing tube solving the aforementioned problems is desired.